How safe is your system in potentially explosive atmospheres really? A spark, leak or electrostatic discharge can have serious consequences, from production downtime to endangering people and the environment. The risk increases, especially in complex automation systems, if components are not harmonised with each other in accordance with standards. That is why effective explosion prevention and protection requires certified, internationally approved solutions that are reliable in every zone, for every industry.
Reliable explosion prevention and protection is based on three levels:
Together, they ensure safe and efficient system operation.
The IECEx system is the globally recognised foundation for the explosion prevention and protection of electrical equipment.
It defines standardised testing and certification procedures based on IEC standards and is used as a reference for national systems in many countries.
What you should know about IECEx:
The ATEX Directive (2014/34/EU) specifies requirements for equipment and protective systems in potentially explosive atmospheres within the EU. It describes how systems, components and accessories are assessed and approved in terms of their ignition sources, zone classifications and equipment categories.
What you should know about ATEX:
The USA and Canada have their own systems for classifying potentially explosive atmospheres: NEC 500 (Class/Division) and NEC 505 (Zone Concept). Certifications are carried out by organisations such as UL (Underwriters Laboratories) and FM (Factory Mutual), which test independently of IECEx.
What you should know about UL / FM:
China has introduced the national CCC Ex system (China Compulsory Certification – Explosion Protection), which replaces the former NEPSI approval. Certification is mandatory for the Chinese market and is based on national GB standards that are based on IEC standards.
What you should know about CCC Ex / NEPSI:
The Brazilian INMETRO system is based on IECEx, but requires local testing by accredited bodies (OCP). INMETRO certification is mandatory for the operation of electric devices in Ex zones.
What you should know about INMETRO:
KOSHA (Korea Occupational Safety and Health Agency) certifies devices for use in potentially explosive atmospheres. The requirements are based on IECEx, but necessitate additional national tests and identification.
What you should know about KOSHA:
In India, the Petroleum and Explosives Safety Organisation (PESO) regulates explosion prevention and protection for equipment in explosive atmospheres. Certification is required by law and is based on IECEx standards with additional national requirements.
This is what characterises PESO:
TIIS (Technology Institution of Industrial Safety) is Japan's national testing system for equipment in potentially explosive atmospheres. TIIS certification is mandatory for market access and ensures that products comply with Japanese safety standards.
What you should know about TIIS:
The ANZEx system is based on IECEx standards, supplemented by country-specific testing and identification requirements. It is the national certification for explosion prevention and protection of electrical equipment in Australia and New Zealand.
This is what characterises ANZEx:
In potentially explosive atmospheres, a distinction is made according to the frequency and duration of the occurrence of an explosive atmosphere. The correct zoning is crucial for selecting suitable components and reliably avoiding the risk of ignition.
An explosive atmosphere in zone 0 is present for longer periods of time or permanently, for example inside tanks, pipelines or reactors. That means this zone is particularly critical in terms of safety and requires materials, seals and temperature resistance of the highest standards. Only specially authorised devices and sensors that do not represent an ignition source even in the event of long-term exposure may be used here.
Areas in which explosive gases or vapours regularly occur during normal operation are classified as zone 1. This is the case, for example, in filling and emptying processes, in gas distribution or mixing systems or when transferring products between reactors and storage tanks. Devices must be designed in such a way that they do not cause ignition even if they come into frequent contact with an explosive atmosphere.
Zone 2 describes areas in which explosive gases, vapours or mists only occur briefly and irregularly, for example in the event of leaks or in the vicinity of compressors and pipe systems. Devices that work safely under normal operating conditions and do not represent a source of ignition even in the event of malfunctions are sufficient.
Zone 20 describes areas in which explosive dust atmospheres are constantly or frequently present, for example in silos or filter systems. The same strict requirements apply here as in Zone 0 for gases: all devices must be protected against dust deposits, heat development and electrostatic charging.
In Zone 21, an explosive dust atmosphere regularly occurs during normal operation, for example in filling systems, mixers or in the vicinity of discharge systems. Devices must be dust-proof and heat-resistant to prevent ignition.
Zone 22 covers areas in which explosive dust atmospheres occur only occasionally, e.g. in packaging, food or conveyor systems. Components used in this zone are reliably protected against dust and temperature increases under normal operating conditions.